* To install 'pwm_handler' on STM32 board, connect uUSB cable to CN5 connector of board and copy the folowing files in 'PYBFLASH' directory:
  - upython/config.json
  - upython/boot.py
  - upython/config.json
  - upython/pwm_handler.py
  - ../common_class/serial_com.py
  - ../common_class/vnh5019.py
  
  * To install client, put the file "pwm_client" located in "client" directory where you want to use it.
  To use client, you need pyserial and tkinter package installed:
  $ python3 -m pip install --user pyserial
  $ sudo apt install python3-tk